UZI PROBLEM

[MGMAN45]

Hello to all, new member here. I have a RR IMI model A that I have owned since the early 80s,have rebuilt it several times over the years. New bolts barrels springs ect. over 150,000 rnds thru the weapon so far has been 100% reliable so far .Recently cut the rear restrictor ring down is all I have done and now am getting failures to eject out of every mag. Am using old IMI mags as well as S.A. from vector which have always proved reliable.What should I be looking for? Also new extractors and recoil springs from vector in at least 3 different bolts. ammo used IMI black tip.Hirt +p+ and WWB. Is it possible the ejector is worn? Thanks for any assistance in this matter. James

 

[RoverDave]

MGMAN45, welcome to UZI Talk.

Based on the variety of parts and ammo you've exchanged, you've eliminated many potential problems and it sounds like it might be related to a barrel alignment issue. Let me understand what mods you did to the gun recently. You said you "cut the rear restrictor ring down". Do you mean you cut it completely off or thinned down the top of the restrictor ring? I assume you cut the top completely off. That's what most people do. Before you cut the ring off, how did the bolt clear the restrictor ring? Is it open bolt? If so, were the bolts modified to pass over the restrictor ring?

You said you cut off the restrictor ring and I assume you didn't do any other changes like enlarge the trunion hole or use a different barrel, right? Typically people will cut off the restrictor ring and enlarge the trunion hole at the same time, allowing them to use full auto barrels. The SMG barrels have a second trunion band that stabalizes the barrel without the restrictor ring. If you've cut off the restrictor ring but still use semi-auto barrels, the barrel might have some play in it causing problems. Even if there's no play in the barrel, it might be sitting at a slightly different angle now without the restrictor ring. One easy thing to check is make sure the barrel nut was not loose. That could cause some alignment problems.

It is possible the ejector could be worn but seems odd that that would occur at the same time you modified the restrictor ring.

 

[MGMAN45]

RoverDave, thanks for the reply, I merely cut the top off the ring and left the sides still there about half the way up.The bolts were not modified to clear the top of the ring. the top of the ring was dremmeled to shave off the thickness at the time of conversion back in 1984. CL2 then transferred the gun to me on a F3. Was CL3 dealer at the time.I had previously thought about barrel having some play at chamber end but it does not. am using SMG barrel that has been milled down to clear both ring and also trunion that has not been opened up.failure to extract has gotten worse with every case not extracting now.this sounds like a weird problem in like you replied it started at the time I cut the ring. any help will be appreciated. Thank You James.

 

[RoverDave]

You could try putting a shim above the barrel on the back side of the trunion to make sure there is no upward movement now that the restrictor ring is removed. I don't know if this is a potential problem but it would eliminate the possibility.

Is the problem extracting the rounds from the chamber or ejecting the case from receiver? Based on your first post I'm assuming the rounds are being extracted from the chamber and then fall into the receiver instead of being ejected out the side.

Another thing to check is make sure the chamber is clean and does not have any burrs or scratches. Anything that would slow down the extraction process could cause ejection problems. If you have a spare barrel, give that a try.

 

[MGMAN45]

RoverDave, I swapped out barrels and the same thing happened. there is no movement at all up or down. I did notice that when the cases do eject they are only thrown out of the port anywhere from 4 to 6 inches.

 

[RoverDave]

The problem sounds like a typical ejection problem, which is either caused by an extractor not holding on to the case very firmly or an ejector problem. Funny that it started when you cut off the restrictor ring. If you've tried a variety of bolts and extractors, it seems unlikely that that is the problem. One option is to send the gun to Vector. I'd have them open up the trunion so you can use unmodified SMG barrels. They probably have to cut a little more off the restrictor ring too if you left the sides on. Then they could test and replace the ejector if necessary.

Why did you cut off the top of the restrictor ring? Not sure what that buys you if you aren't doing a full conversion to allow SMG barrels.

 

[MGMAN45]

Thanks RoverDave for the help. Im probably going to go ahead and let Vector diagnose the problem. The reason I cut the top out was because I noticed rub marks on top inside of bolt over the years and I guess I had too much time on my hands that day.Gonna call Vector today and see what they have to say about it. I appreciate the help and will post an update when this is resolved. Thank You Sir. James

 

[RoverDave]

One more thought. Make sure the remaining restrictor ring is not dragging on the bolt, slowing it down. When cutting off the top, it's possible that the sides of the ring were bent or there might be a burr that is rubbing on the bolt. Anything that slows the bolt down can cause ejection problems. You might just want to cut off the remaining sides of the restrictor ring. For reference, check out the bottom picture here.

 

[AK43]

Taking the barrel restricter ring off of a R/R uzi

I too had an imi uzi that had the ring in it and it shot accuratly but I had found a 45 bolt and it would not clear the barrel ring. Group Industries made a 9mm bot that would clear the ring. Anyway to get back on track as soon as i take the ring off all the way down to where the barrel sets on top of the feedramp. The gun was very unaccurate. I could go on and on about what all else I did to try and correct it to no avail. I sent it to Vector for it to be converted to SMG specs, bore trunion, and mill out the rest of the barrel rest that was connected tbo the feedramp. That was the end of the problems. I just hope you don't have to wait as long as I did. good luck